Short answers, pulled from the story.
The Baltic Way was a peaceful political demonstration held on the 23rd of August 1989, in which approximately two million people joined hands to form a human chain spanning 675 kilometres across Estonia, Latvia, and Lithuania. The date marked the 50th anniversary of the Molotov-Ribbentrop Pact, the Soviet-Nazi agreement that led to the occupation of the Baltic states.
The human chain stretched 675 kilometres, connecting the three Baltic capitals of Vilnius, Riga, and Tallinn. Participants joined hands for 15 minutes at 19:00 local time.
The Estonian Rahvarinne, the Latvian Tautas fronte, and the Lithuanian Sąjūdis organised the event. Their primary goal was to draw global attention to Baltic independence and demonstrate solidarity among the three nations.
Western estimates placed participation between one and two million people. Reuters reported approximately 700,000 Estonians and 1,000,000 Lithuanians joined, while the Latvian Popular Front estimated roughly 400,000 Latvian participants.
On the 26th of August 1989, the Central Committee of the Communist Party delivered a 19-minute televised warning describing the movements as nationalist extremists and calling their actions a "nationalist hysteria." Moscow issued implicit threats of force but failed to follow through, and historian Alfred Erich Senn later described the statement as a source of embarrassment.
On the 11th of March 1990, Lithuania became the first Soviet republic to declare independence, within seven months of the demonstration. In February 1990, pro-independence candidates had won majorities in the first free democratic elections held across all three Baltic states, and the independence of all three was recognised by most Western countries by the end of 1991.
August 23 is observed as the Black Ribbon Day, or the European Day of Remembrance for Victims of Stalinism and Nazism, because it marks the anniversary of the 1939 Molotov-Ribbentrop Pact. The date became an official remembrance day in the Baltic countries and the European Union following the Revolutions of 1989.